1. Field of the Invention
The present invention is related to an improved structure of hand tool, and especially to a hand tool suitable for fast changing a grinding member during operation.
2. Description of the Prior Art
The inventor of the present invention had provided an xe2x80x9cImproved Structure of Multi-functional Hand Toolxe2x80x9d which was granted with a patent of utility model in Taiwan with a patent publish number of 447,362 and granted with a patent of invention in U.S.A. with a patent number of U.S. Pat. No. 6,202,760B1; the main structure of the hand tool, as shown in FIGS. 1 and 2, comprises a chuck 60, a positioning sleeve 14, a pushing axle-rod 50, a pushing member 40, a pipe 70 and an outer sleeve 80.
With the above members, the chuck 60 and the pushing axle-rod 50 are extended into the positioning sleeve 14 respectively from two ends of a central axle hole of the latter, a bolt on the front end of the pushing axle-rod 50 is screw connected with an inner thread of the chuck 60, a spring slipping over the pushing axle-rod 50 is exactly pressed against between an annular protrusion and a stop ring of the positioning sleeve 14; a rear bolt on the rear end of the pushing axle-rod 50 is screw connected with a driving rod, and an outer annular member for the positioning sleeve 14 is slipped in two sliding bearings 142, then the positioning sleeve 14 is placed together with pushing axle-rod 50 and the chuck 60 into the pipe 70 to render the positioning sleeve 14 able to rotate on the sliding bearings 142, a front inner thread of the pipe 70 is connected with an outer thread of a front collar, so that the chuck 60 is extended out of the front end of the front collar.
The pipe 70 has a rear inner thread on the rear end thereof locked into the pushing member 40, so that a cylindrical rod on the front end of the pushing member 40 abuts against the rear area of the annular protrusion of the pushing axle-rod 50; while a hole on a thread portion of the outer annular member of the pushing member 40 is exactly located at the position where a position-limiting annular groove of the pipe 70 is. The rear end of the pipe 70 is slipped in the outer sleeve 80, and an inner screw hole of the outer sleeve 80 is aligned with the position-limiting annular groove of the pipe 70, then a positioning bolt is locked into the inner screw hole to extend through the position-limiting annular groove and the hole on the pushing member 40 to complete the hand tool.
From the above disclosed structure of the xe2x80x9cImproved Structure of Multi-functional Hand Toolxe2x80x9d, it has the pushing member 40 moved mainly by rotating of the outer sleeve 80, so that the pushing member 40 and the outer sleeve 80 are moved synchronically; and by using the pushing member 40 to push the pushing axle-rod 50, while the pushing axle-rod 50 is connected by locking with the chuck 60, when the pushing axle-rod 50 is pushed by the pushing member 40, it moves the chuck 60 and pushes the chuck 60 toward the outside of the pipe 70 to make the chuck 60 become a loosened state, and now a grinding member 90 can be changed.
However, such a structure must have the grinding member 90 changed under the state that the hand tool is stopped. By virtue that the pushing axle-rod 50 is linked up with the driving rod, when the pushing axle-rod 50 is pushed by the pushing member 40, the pushing axle-rod 50 will generate an axial pulling force against the driving rod, this tends to damage the axle.
Therefore, the inventor of the present invention provides the improved structure of hand tool based on his professional experience of years in studying, designing and manufacturing same kind of products and after hard study, developing, as well as repeated experiments and tests, in order to make the hand tool get the object of changing a grinding member fast, and to avoid the axle from damage, the structure for changing of it is perfect.
The present invention mainly comprises a first pipe, a second pipe, a rotating sleeve, a pushing member, a pushing axle-rod and a chuck, it is characterized in that: the first pipe is provided thereon with a position-limiting slot and a plurality of positioning holes, the positioning holes are provided for extending therethrough of two position-limiting elements; the first pipe is provided thereon with an elastic piece for abutting against the position-limiting elements; the rotating sleeve is slipped over the first pipe, and is provided thereon in opposition to the position-limiting slot with a hole for extending of a pivotally-connecting element therein to connect and lock the pushing member, the hole has on the inner wall thereof a positioning groove to engage the position-limiting elements and to make an effect of positioning with the elastic piece; the pushing member is slipped over the pushing axle-rod, the pushing axle-rod has a bearing slipping thereover; and one end of the pushing axle-rod is brought to rotate by a driving element, the other end is pivotally connected with the chuck, and assembling of the hand tool thus is completed.
The object of the present invention is to have the pushing member moved mainly by rotating of the rotating sleeve, so that the pushing axle-rod is endued with an axial pushing force to make the chuck to push toward the outside of the first pipe to make the chuck become a loosened state; by virtue that the pushing axle-rod has a bearing thereon, when the pushing axle-rod is driven by the driving element, the pushing axle-rod can keep on operating to avoid being blocked, thereby the hand tool able to fast change the grinding member during operation can be provided.
Another object of the present invention is resided in that: the driving element is provided in the second pipe, and the driving element is connected with an electric power-line by insertion connecting through a connecting device to allow a user to change the driving element by himself.